Eleven people have been confirmed dead in a flood that occurred Friday morning following a dam breach in East China’s Zhejiang province, as rescuers retrieved the body of a woman on Saturday.

The body was found about one km downstream from the Shenjiakeng Reservoir, a rainwater pooling dam in Daishan county in the city of Zhoushan, said a statement by the county government.

“It took only few minutes for the dam to collapse. Some people escaped to places where water levels were low, while others had to stay in their homes,” recalled one resident who managed to escape his flooded house.

The 10 victims killed included six females and four males. Seven of them are older than 74, and one is a 12-year-old child, according to an official statement from the local government. The oldest victim is 87. It also said that at least 80 local families have suffered as a result of the disaster.

“Most of the houses are made from stones and clay, which was very easily washed away by floods,” said Chen Fu, chief of the Zhoushan firefighting branch, speaking at the site during a phone interview with the local radio station, about six hours after the collapse.

Sitting on the north of Zhoushan, the fishing and shipping hub of the highly industrialized Yangtze River Delta, Shenjiakeng village is largely populated by migrant workers from other cities who work at ship-manufacturing companies.

Officials said the fact that many migrant workers lived in the village has “added to the difficulties of locating and identifying the missing”.

“I don’t think [the rescue effort] is very effective,” she added. “It happened very early [this morning] but when people were calling in for help, it seems that people didn’t reach them until much later.”

Asked if the authorities had reported the full extent of casualties, she said: “The media is bound to try to suppress this.

“Teams of experts were sent to the scene, while local rescue teams vowed “all-out efforts” to locate the missing, the English-language China Daily newspaper reported in the wake of torrential rains which have lashed China’s eastern seaboard at the trailing edge of typhoon Haikui.

Some netizens posted to popular microblogging services that the Shenjiakeng dam was old and had been falling into disrepair since the local government had handed it over to a private entrepreneur who was running a water purification plant at the reservoir.